Conventionally, a navigation apparatus or the like in a vehicle uses external information such as congestion information acquired from information infrastructure by a receiver apparatus, and the receiver apparatus that feeds the navigation apparatus with the external information for display deletes the external information acquired from outside of the vehicle if the navigation apparatus has been turned on for a certain period that is greater than a preset time period from a reception time of the external information from outside of the vehicle by the receiver apparatus. For example, the disclosure in Japanese patent document JP-3186330 describes an information deletion scheme described above.
However, the receiver apparatus keeps using the external information until the preset time period lapses. That is, in other words, even if new external information is available during the preset time period, the new external information will not be used by the receiver apparatus and the navigation apparatus.
Further, even if a validity time of the external information is longer than the preset time period, the external information is deleted when the preset time period has elapsed from a turn-on time of the navigation apparatus.